Isopropoxycarbonyl dimethyldithio-carbamate



ted States Pa 'fitr ISOPROPOXYCARBONYLipMETHYEITfiI0 .CARBAMATE Chien-Pen L and W E Craig, Philadelphia,'l'a., assignors =to Rohmw HaaiCompanyfil hiladblphia; Pa.,-*a corp ration of Delaware 3 Claims. (Cl. 167-22) 'This invention concerns isopropoxycarbonyl "dimethyl- I dithioc'arbamate and its use 'as" a fung'icid e for-protecting ltlimethyldithiocarbam'ate and found that' t hese too -were t unstable. These '=va'rious esters wereso un's'table that they could not be prepared in a metal apparatus, the metal surfaces apparently catalyzing decomposition.

In contrast to the above observations, we found unexpectedly that isopropoxycarbonyl dimethyldithiocarbamate, which is a solid, is relatively stable, and it has been stored at room temperature over a considerable period of time without any change in composition. Furthermore, it has sufficient stability to be made in metal equipment.

This compound is prepared by reacting a soluble salt of dimethyldithiocarbamic acid with isopropyl chloroformate. The reaction is most conveniently elfected in an inert solvent, such as dimethylformamide, acetone, benzene, ethers, or even Water at a temperature below about 20 C., a range of to C. being generally useful.

For example, solid anhydrous sodium dimethyldithiocarbamate (315 parts by weight) was dissolved in 915 parts by Weight of dimethylformamide. T 0 this solution, cooled to about 10 C., was slowly added 245 parts by weight of isopropyl chloroformate, while the mixture was stirred and maintained. below 10 C. by external cooling. The reaction mixture was further stirred for an hour. It was poured into 3000 parts of water. A yellow solid formed. It was filtered off, washed with water, and dried in air to give 386 parts of product. This material corresponded in composition to isopropoxycarbonyl dimethyldithiocarbamate. It'melted at 6l-62 C. After it was recrystallized from ethanol, the melting point was still 6162 C. The nitrogen analysis was 6.8% and the sulfur analysis was 30.3% (theory 6.8% and 30.9% respectively).

In another preparation, 717 parts of isopropyl chloro formate were slowly added to a solution of 2200 parts of sodium dimethyldithiocarbamate in a mixture of 4440 parts of water and 800 parts of acetone which was cooled below 10 C. by means of an ice bath. The mixture was stirred for an hour. About 800 parts of water was added and the resulting mixture was stirred for a half hour. A yellow solid formed, was filtered ofr, and was dried to give 855 parts of product. It gave an analysis corresponding to that of isopropoxycarbonyl dimethyldithiocarbamate. It melted at 6061 C.

Samples of the above product were left in contact with It was noted that others have indicated that this Pateni:ed=- May 20, 1958 --;'strips of. iron, stainless steel, and copper atsteam bath -temperaturesfor over-24 hours without evidence of det-composition. A-portion was heated: for two hours-at 100 C. on strips of iron, likewise without-decomposion. '.Anothensample-was-heated to.-160 -C. -without decomposi-tion.

In contrast, a samplea-of ethoxycarbonyl dimethyldi- -.thioc.arbamate was-warmed on-an iron su-rface on-a steam ;bath. a A. copious evolutionofi gas rapidly-occurred, leav- 10 ing: aresidue containing no sulfur 'and being fungicidally dinaotive.

- In standard fungitoxicity tests,'isopropoxyearbonyl di- .methyldithiocarbarnatewas"- found tothaveanLD -walue of l to 5.:p.-p. In. againstboth Stemplzylizlmsarcina eforme I5 I andMonilinia fructicola.

Wealso .prepared isobutoxycarbonyl-dimethyldithiocarbamate (from -sodiumdimethyldithiocarbamate I. and isobutyl chloroformate) I This-compound is anoil. -We likewise prepared sec-butoxycarbonyladimethyldithiocar- 20.bamate,. also an oil. aBoth-showedrgoodtfungitoxicity, having.-LD -va1ues-of 5-7.5 .p: p. and 10,-p.;p."m. respectively. Neither, however, was stable --on -=rnetal surfaces.

tdsopropoxycarb onyl dimethyldithiocarbamate.t may be formulated in. dusts,'-wettable powders, on emulsion con- 3 centrates-. for protecting, plants Tagainst attack aby fungi.

These preparations may be-appliedto. or a'bouttanyplant organ, including seed, stern, leaf, or fruit. Thus, this compound can be mixed with a neutral or acid clay, talc,

or other conventional, finely divided solid diluent. Basic diluents are to be avoided. Finely divided sulfur is a good diluent and also an active agent.

The compound may similarly be extended with an inert organic solvent together with solvent-soluble emulsifying agent. This is a peculiar and unique property of this substance, for as far as we can determine, there is no other effective fungicide which can be used in an emulsifiable concentrate. Such compositions are usually diluted with water for application, as for spraying on foliage or into soil.

An emulsion concentrate can be. made, for example, from 25 parts of isopropoxycarbonyl dimethyldithiocarbamate, 70 parts of an aromatic naphtha, one part of calcium dodecylbenzenesulfonate, and four parts of tert- 4 octylphenoxypolyethoxyethanol wetting agent.

A typical wettable powder may be made by mixing 25 parts of isopropoxycarbonyl dimethyldithiocarbamate,

73 parts of a clay having a pH of 6, one part of a condensed naphthalene-formaldehyde sodium sulfonate, and

one part of dry mixture containing 20% of an octyl-,

phenoxypolyethoxyethanol wetting agent on magnesium carbonate. Wettable powders may be applied from aqueous sprays or used in dusts.

A 5% or 10% dust may be similarly prepared, the wetting and dispersing agents being reduced in amount or even omitted. Dusts may be applied to plants by being blown onto foliage, by being mixed with soil, or by being dusted onto seeds.

In plate tests isopropoxycarbonyl dimethyldithiocarbamate at 10 p. p. m. was found to prevent growth of such typical fungi as Sclerotinia rolfsii (southern blight of legumes), Sclerotinia sclenotiorum (stem rot of s'oya bean), Rhizoctonia sola ni (damping off of cotton), Pythium ultimum (root rot of muskmelon, seedling blight of lettuce, pear, corn, etc.), Pythium aphanidermatum (pythium root rot of cucurbits), Phytophthora citrophthora (fruit rot of citrus trees), Phytophthora cinnamomi (phytophthora root disease of avocados, pineapple, and chestnut), Phytophthorw cactorium (root rot of clover,

crown rot of walnuts), Armillaria mellea (oak root fungus), and others, including Streptomyser scabies and clerotium rolfsii. The compound has also been shown Methods-of to be effective in admixtures with soils. test are described by Zentmyer in Phytopathology 45, 398 (1955). At levels of 10 to 100 p. p. m in soils isopropoxycarbonyl dimethyldithiocarbamate is effective'in controlling pathogens which incite diseases of 'underground origin of numerous and diverse importantfagricultural crops.

The compound has been exposed to ultraviolet light from an are for a period of four hours and then biologically evaluated. No loss in activity was observed' It can be used in conjunction with other non-basic fungicidal agents, insecticides, miticides, and the like.

For example, for an excellent, all-purpose garden spray, there can be mixed 22 parts of 1,l-bis(chlorophenyl)-2,2- dichloroethane, 11 parts of 1,1-bis(chlorophenyl)-2,2,2- trichloroethanol, 6 parts of lindane (gamma isomer of hexachlorocyclohexane), 11 parts of isopropoxycarbonyl dimethyldithiocarbamate, 8 parts of an oil soluble emulsifying agent or composition, and 42 parts of an aromatic naphtha. A useful emulsifying composition can be composed of one part of the calcium salt of dioctyl succinosulfonic acid and three parts of a tert-octylphenoxypolyethoxyethanol. This composition has been found stable even after storage of about a year, as measured by biological tests. i

Isopropoxycarbonyl dirnethyldithiocarbamate may likewise be mixed with such an insecticide as bis(diethylphenyl)dichloroethane or as malathion, or with the miticide and fungicide dinitrocaprylphenyl crotonate, or with mixtures of these various agents.

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A peculiar property of isopropoxycarbonyl dimethyldithiocarbamate is found in its capacity to control varidimethyldithiocarbamate.

2. A process for controlling fungi on living plants which comprises supplying to a fungus-infested environment thereof isopropoxycarbonyl dimethyldithiocarbamate.

3. A process for controlling disease-causing micro-organisms on the underground portions of plants which comprises supplying to a fungus-infested environment of said portions isopropoxycarbonyl dimethyldithiocarbamate.

References Cited in the file of this patent UNITED STATES PATENTS Twiss et al. June 29, 1937 Swaney et al. Feb. 13, 1951 OTHER REFERENCES Quevauvill er et al.: Chem. Abs. 46, col. 4175 (1952). Kerk et al.: Rec. Trav. Chim. 71, pp. 1179-97 (1952). 

1. AS A NEW CHEMICAL COMPOUND, ISOPROPOXYCARBONYL DIMETHYLDITHIOCARBAMATE.
 2. A PROCESS FOR CONTROLLING FUNGI ON LIVING PLANTS WHICH COMPRISES SUPPLYING TO A FUNGUS-INFESTED ENVIRONMENT THEREOF ISOPROPOXYCARBONYL DIEMTHYLDITHIOCARBAMATE. 